Problem: $ { \left[\begin{array}{r}{1} \\ {2} \\ {4}\end{array}\right]-\left[\begin{array}{r}{3} \\ {4} \\ {4}\end{array}\right] = {?} } $
Answer: To find the difference of two matrices, subtract the corresponding items between each matrix. ${\left[\begin{array}{r}{1}-{3} \\ {2}-{4} \\ {4}-{4}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{r}{-2} \\ {-2} \\ {0}\end{array}\right]}$